Power supply apparatus

ABSTRACT

Disclosed herein is a power supply apparatus that includes a bearing plate, insulation material and a plurality of pins. The insulation material is formed on two opposite surfaces of the bearing plate. The plurality of pins are electrically connected to the bearing plate and allocated along lateral sides of the insulation material.

RELATED APPLICATIONS

This application is a divisional application of U.S. patent applicationSer. No. 14/840,063, filed on Aug. 31, 2015, which claims priority toChina Application Serial Number 201410442972.6, filed Sep. 2, 2014, allof which are herein incorporated by reference.

BACKGROUND Field of Invention

The present invention relates to a power supply apparatus. Moreparticularly, the present invention relates to the internal structure ofa power supply apparatus.

Description of Related Art

With people's increased demand to the intelligent life, the society'sneed to data processing is also growing. The global energy consumptionspent on data processing averages thousands or even tens of thousandskilowatt-hour (KWH); and a large scale data center may occupy tens ofthousands square meters. Therefore, a greater efficiency and higherpower density are the key index for the healthy development of thisindustry.

The key component of the data center is the server, which has a mainboard that usually composed of data processing chips such as CPU,chipsets, memory, etc., and the power supply and necessary peripheralcomponents thereof. With the improvement of the processing capability ofthe server unit volume, the numbers of these chips and the integrationlevel thereof are also increased, which results in the increase of thespace occupied and the power consumption. Therefore, the power supplyfor supplying these chips (also referred to as the main board powersupply because it is disposed on the same main board as the dataprocessing chip is) is expected to exhibit greater efficiency, higherpower density and more compact volume, so as to realize theenergy-saving of the whole server or event the whole data center andreduction of the floor space.

In the server, the main board PCB is configured to transmit the energyand signal. On the main board PCB, a data processing chip and a powersupply thereof are disposed. The height of the casing of the server isoften a standard value, which is defined using the industrial standard“U”; for example, 1U, 1.5U, 2U, etc. (1U=1.75 inch=44.45 mm). Forexample, for a server with a height of 1U (about 40 mm; the actual sizeof the 1U device may vary due to the fit tolerance), the main board is aPCB consisting of 6 to 50 layers, which is very expensive tomanufacture. In the case where the height of the server casing islimited, in order to ensure the expected efficiency, by reducing thearea that the main board power supply occupies on the main board (thatis, the horizontal area of the main board power supply), it is possibleto reduce the over volume, increase the power density, and accordingly,lower the manufacturing cost. In the present disclosure, the power ofthe power supply unit horizontal area is referred to as the “powerpressure”.

When using the same technology level in designing a power supply havinga power of Po, the greater the volume (V) of the power supply, theeasier to achieve a higher efficiency; that is, the power efficiency ispositively proportional to the volume (V). The volume (V) equals to theproduct of the height (H) and the horizontal area (S). The powerpressure (Pp) equals to Po/S. If the efficiency is fixed at a specificlevel (meaning the efficiency is kept the same), the followingrelationship between the power pressure (Pp) and the height (H) could bederived: the greater the H, the greater the Pp. In other words, toimprove Pp, we should focus on the utilization of the height (H) for asolution. Of course, if the goal is to pursue the efficiency, the heightshould be properly utilized based on the foregoing rationale. Therefore,how to utilize the height is the key to address both the power pressure(Pp) and the efficiency.

The thickness or height of the main board power supply can be as thin as7 mm or even less; hence, when the height of the server is limited to,say 1U, there are more than 20 mm of space height above the power. Inthis case, the efficiency can be 90% or higher, since the powerconsumption thereof is only a fraction (such as 10%) of the dataprocessing chip, in fact, it is possible for it to handle the heatdissipation issue without using a heat dissipation unit. In this way,the space above the main board power supply is not adequately utilized.

Generally, there two ways to manufacture the main board power supply.The first one uses a PCB as the bearer on which individual componentsare installed. After years of efforts, this type of main board powersupply achieves satisfactory efficiency and power density. Yet, sincethe components are individually installed, there should be necessaryspace or safety distance between components, thereby limiting thefurther size reduction of the horizontal area; also, the uneven heightwould affect the subsequent handling of the heat.

The other way to manufacture the main board power supply is to usecertain packaging technique to integrate each components of the powersupply into a quite regular element. By using such packaging techniques,the power density is significantly increased with satisfactoryefficiency; also, such regular shape is advantageous for the subsequenthandling of the heat; thereby providing an appropriate solution.However, said packaging technique realize the volume reduction and powerdensity improvement by lowering the height of the main board powersupply, and hence, it focuses on decreasing the height based on theoriginal horizontal area. Therefore, this solution is only one of thesolution for pursuing a better power density; however, it cannotadequately address the improvement regarding the power pressure of themain board power supply.

SUMMARY

The following presents a simplified summary of the disclosure in orderto provide a basic understanding to the reader. This summary is not anextensive overview of the disclosure and it does not identifykey/critical components of the present invention or delineate the scopeof the present invention. Its sole purpose is to present some conceptsdisclosed herein in a simplified form as a prelude to the more detaileddescription that is presented later.

The present invention addresses the deficiency of the prior art andprovides a novel solution that deals with both the power pressure andthe efficiency; it is suitable for use in application settings requiringa larger horizontal area; such as the demand for power supply in dataprocessing settings like the data center.

In one embodiment, a power supply apparatus includes a bearing plate,insulation material and a plurality of pins. The insulation material isformed on two opposite surfaces of the bearing plate. The plurality ofpins are electrically connected to the bearing plate and allocated alonglateral sides of the insulation material.

In one embodiment, a power supply apparatus includes a bearing plate,insulation material and at least one pin. The insulation material isformed on two opposite surfaces of the bearing plate. The at least onepin is electrically connected to the bearing plate and contacting atleast part of the insulation material.

In view of the foregoing, the technical solutions of the presentdisclosure result in significant advantageous and beneficial effects,compared with existing techniques. The implementation of theabove-mentioned technical solutions achieves substantial technicalimprovements and provides utility that is widely applicable in theindustry. The present disclosure provides a stack structure so that theheight of the power supply can be properly utilize; when the volume isfixed, it is possible to achieve a smaller floor space; meanwhile, itretains sufficient volume to ensure a higher efficiency, therebyaddressing both the high power pressure and high efficiency. Also, itsupports the data processing apparatus with better performances.

Many of the attendant features will be more readily appreciated, as thesame becomes better understood by reference to the following detaileddescription considered in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The present description will be better understood from the followingdetailed description read in light of the accompanying drawing, wherein:

FIG. 1 is a lateral view illustrating a power supply apparatus accordingto one embodiment of the present disclosure;

FIG. 2 to FIG. 14 illustrate the infrastructure and distribution ofstack component of the power supply according to embodiments of thepresent disclosure;

FIG. 15 to FIG. 16 illustrate the embodiments covered by the controlunit and the power unit according to embodiments of the presentdisclosure;

FIG. 17 to FIG. 20 illustrate the stack structure design according toembodiments of the present disclosure;

FIG. 21 to FIG. 25 illustrate the pin arrangement according toembodiments of the present disclosure;

FIG. 26 illustrates the infrastructure for heat dissipation according toembodiments of the present disclosure; and

FIG. 27 illustrates the arrangement of the magnetic core according toembodiments of the present disclosure.

DETAILED DESCRIPTION

In the following detailed description, for purposes of explanation,numerous specific details are set forth in order to attain a thoroughunderstanding of the disclosed embodiments. In accordance with commonpractice, like reference numerals and designations in the variousdrawings are used to indicate like elements/parts. Moreover, well-knownelements or method steps are schematically shown or omitted in order tosimplify the drawing and to avoid unnecessary limitation to the claimedinvention.

In the detailed description and appended claims, the term “coupled with”applies generally to that one component is indirectly connected toanother component via other component(s), or one component is directlyconnected to another component without any other component.

On technical aspect of the present invention is a power supplyapparatus, which can be used in a server or more generally in varioustechnical fields. It should be noted that the power supply apparatusaccording to this aspect uses the stack structure, and therefore, theheight of the power supply can be properly utilized so that a smallerfloor space can be realized when the volume is fixed.

FIG. 1 is a lateral view illustrating a power supply apparatus accordingto one embodiment of the present disclosure. As illustrated in FIG. 1,the power supply application device (e.g., a power supply apparatus)comprises a main board 110, a power unit 120, a control unit 130, and apin 140. The main board 110 further has a load 150 disposed thereon; thepower unit 120 is disposed on the main board 110; the control unit 130and the power unit 120 are stacked on the main board 110 at a positionin adjacent to the load 150; the pin 140 is electrically coupled to themain board 110, the control unit 130, and the power unit 120; in thepresent embodiment, there are multiple pins 140 and these pins arerespectfully disposed on a lateral side of each of the power unit 120and the control unit 130; the two power units 120 and the control unit130 are stacked with one another on the main board 110. The control unit130 is configured to control the power unit 120; specifically, thecontrol unit controls the two power units 120 via the pins 140, so thatthe power unit 120 supply the electricity to the adjacent load 150. Theload 150 is a digital processing IC, such as a central processing unit(CPU), and the CPU has a heat dissipation unit/heat dissipation devicesuch as a heat dissipater 151 disposed thereon. The power unit 120comprises at least one power semiconductor device (such as, switch tubesS21, S22, S23, S24 in FIG. 3, switch tubes S21, S22, S23, S24, S31, S32,S33 in FIG. 11); the control unit 130 comprises at least one chip havingthe control or driving ability (such as, the control circuit 310 in FIG.3, the control circuit 1100 in FIG. 11, DSP).

In one embodiment, the power supply apparatus is disposed on the mainboard 110; the main board 110 further has a load 150 of a dataprocessing chip (such as, CPU) disposed thereon; the power supplyapparatus comprises: the power unit 120, the control unit 130 and pins140. The control unit 130 and the power unit 120 are stacked on the mainboard at a position in adjacent to the load 150; the pins areelectrically coupled to the main board 110, the control unit 130 and thepower unit 120; the control unit 130 is configured to control the powerunit 120, so that the power unit 120 supplies the electricity to theadjacent load 150.

In sum, the DC/DC power supply comprises at least two units (i.e.,modules): the control unit 130 and the power unit 120. Said two modulesare vertically stacked, and the electric connection therebetween isrealized via the conductors (i.e., pins 140) so as to transmit theelectric signal. The power unit 120 comprises at least one activeswitching element; the power unit 120 receives the input power andgenerates a corresponding output power by the conduction and turning-offof the active switching element and then supplies the output power tothe load 150, such as the data processing chip. The control unit module130 comprises at least one control chip for sending a control signal tothe active switching element of the power unit 120 so as to control theconduction and turning-off of said element. The unit disposed at theupper position and a portion of the pins are fixed by the unit disposedat the lower position, and then transmits the electric signal to theabove-mentioned main board 110 (such as, the PCB).

In this way, due to the stack structure adopted herein, the height ofthe power supply can be more properly utilized so as to realize asmaller floor space at a given volume; while retaining sufficient volumeto ensure a higher efficiency; accordingly, it accomplishes both thehigh power pressure and high efficiency. Also, it supports the dataprocessing apparatus with better performances.

Infrastructure and Distribution of Stack Component of the Power Supply

FIG. 2 is a schematic diagram illustrating various types of power supplyconverter (i.e., the main board power supply 200) that may involve in aserver main board. The input of the power supply converter is often adirect current with a wide range of voltage, including high voltage of200 to 500 V (for example, 400 V), middle voltage of 18 to 72 V (forexample, 48 V) and low voltage of 5 to 15 V (for example, 12 V). Nomatter what kind of voltage is being inputted, a corresponding DC/DCconverter is required to convert the input into a desired output to besupplied to the load 150, such as the data processing chip, like acentral processing unit (CPU) and memory. The variation range of theoutput is also wide so as to adapt to the demands of various loads; forexample, the output can be as low as 0.8 V or even lower, or as high as12 V or even higher. When the load 150 is a CPU and memory, the outputvoltage is often in the range of 0.8 to 2 V. Therefore, the power supplyspecification involved includes, mainly:

(1) Converter 210 converts 400 V to 48 V: the input voltage is in arange of 200 to 500 V (for example, 400 V) which is outputted as astable output voltage or at a fixed ratio to the input voltage; forexample, the output voltage can be around 48 V or a voltage in the rangeof 18 V to 72 V. Since the output voltage is higher, it will not bedirectly connected to the data processing chip load; instead, anotherspecification converter should be cascaded thereafter to adjust thevoltage to a level that can be used by the load.

(2) Another a converter (not shown in the drawing) coverts 400 V to 12V: the input voltage is in a range of 200 to 500 V (for example, 400 V)which is outputted as a stable output voltage or at a fixed ratio to theinput voltage; for example, the output voltage can be around 12 V. Sincethe output voltage is lower, it can be connected to some data processingloads, such as a hard drive. However, when the load voltage is evenlower; for example, 0.5 to 5 V, another specification DC/DC convertershould be cascaded thereafter to adjust the voltage to a level that canbe used by the load.

(3) Yet another converter (not shown in the drawing) converts 400 V to0.5 to 5 V: the input voltage is in a range of 200 to 500 V (forexample, 400 V) which is outputted as a stable output voltage dependingon the actual need; for example, the output voltage is in the range of0.5 to 5 V. The output voltage can be directly connected to the dataprocessing chip, such as the CPU, memory, etc.

The converts according to the above-mentioned specification (1) to (3)use a high-voltage input, and hence, they should meet the requirementsfor high voltage safety insulation, and the insulation voltage should bearound a DC voltage of 2000 V, or even higher.

(4) Converter 220 converts 48 V to 12 V: the input voltage is in a rangeof 18 to 72 V (for example, 48 V), which is outputted as a stable outputvoltage or at a fixed ratio to the input voltage; for example, theoutput voltage can be around 12 V, or in the range of 3 to 15 V. Theconverter of this specification can be directly connected to some dataprocessing loads, such as a hard drive.

(5) Converter 230 converts 48 V to 0.5 to 5 V: the input voltage is in arange of 18 to 72 V (for example, 48 V) which is outputted as a stableoutput voltage depending on the actual need; for example, the outputvoltage is in the range of 0.5 to 5 V. The output voltage can bedirectly connected to the data processing chip, such as the CPU, memory,etc.

(6) Converter 240 converts 12 V to 0.5 to 5 V: the input voltage is in arange of 3 V to 15 V (for example, 12 V) which is outputted as a stableoutput voltage depending on the actual need; for example, the outputvoltage is in the range of 0.5 to 5 V. The output voltage can bedirectly connected to the data processing chip, such as the CPU, memory,etc. Since this converter uses the low-voltage input, there is no needfor insulation, and the output can be directly connected to the dataprocessing chip, such as the CPU, memory, etc.

The converts according to the above-mentioned specification (4) to (6)use a low-voltage input, and hence, the voltage-bearing demand of theconverters is lower, which is generally less than a DC voltage of 2000V.

When the output of the converter is 0.5 to 5 V, since the output can bedirectly connected to the load 150, such as the data processing chip,the power supply converter is required to output a low-voltage highcurrent, and a high dynamic responsive ability is required, for example,when the load 150 is a CPU, a responsive ability of 1000 A/ns isrequired; and in this case, the power supply converter should bedisposed in adjacent to the load. Therefore, such power supplies arereferred to as the “point of the load”. Among them, the power supply forsupplying the CPU (also known as the voltage regulated module (VRM)) isrequired to supply the electricity from an adjacent position.

The power supply converters having the above-mentioned input/outputspecifications are all disposed on the main board; hence, they can bestacked to achieve the goals of high power pressure and high efficiency.Of course, the combination of various converters is also appropriate forthe stack arrangement.

As described above, the power supply having an input of 400 V or 48Voften requires an input/output safety pressure tolerance due to thegreater pressure difference between the input and output, and it oftenuses a transformer to isolate and transmit the energy. Of course, ifnecessary, for example, to realize a wider input or output range, alow-voltage input power supply (such as a power supply having an inputof 12 V) can also use a transformer to transmit the energy.

The converters according to the above-mentioned specifications canemploy various type of topology to achieve the conversion of theelectric energy, for example, the pulse-width modulation (PWM)-basedforward circuit, full-bridge circuit, phase-shift full-bridge circuit,half-bridge circuit, fly-back circuit, etc. To realize a higher powerdensity, a higher operation frequency is often required, for example,500 kHZ, 1 MHZ, or even more than 2 MHZ. To achieve a high efficiencyunder such high frequency, a resonant circuit (that is, apulse-frequency modulation (PFM)-type LLC series resonant converter(LLC-SRC), parallel resonant converter (PRC), etc.) is often selected.

FIG. 3 illustrates a half-bridge LLC circuit. As illustrated in FIG. 3,the circuit comprises a main circuit and a control circuit 310. The maincircuit comprises: an input capacitor C1, a resonant capacitor C2, aresonant inductor L1, a transformer T1, primary side switch tubes S11,S12 and secondary side switch tubes S21, S22, S23, S24, wherein theinput capacitor C1 is connected with the primary side switch tubes S11,S12; the primary side switch tubes S11, S12 is connected with a seriescircuit composed of the resonant capacitor C2, the resonant inductor L1,the primary winding of the transformer T1; the secondary winding of thetransformer T1 is connected with the secondary side switch tubes S21,S22, S23, S24; the output capacitor C3 is connected with the secondaryside switch tubes S21, S22, S23, S24. The primary side switch tubes S11,S12 receive the input power and convert the DC input signal into a ACsignal; the AC signal is transmitted to the secondary side via theresonant inductor L1, the resonant capacitor C2 and the transformer T1,and then passed through the secondary side synchronous rectifyingcircuit (such as, the secondary side switch tubes S21, S22, S23, S24),and generates an output voltage on the output capacitor C3 and suppliesthe output power to the load. It should be noted that since the outputis a low-voltage high current, to reduce the loss, the elements withlow-voltage high current (such as the T1 secondary winding, thesecondary rectifier, the output capacitor) are often in parallelconnection to obtain a low resistance. For example, “an assembly of arectifying assembly S21, S22 and a secondary winding” and “an assemblyof another rectifying assembly S23, S24 and another secondary winding”are in parallel connection. Since the output voltage may vary, thestructure of the transformer secondary winding is not limited to thecentral tap rectifying structure illustrated in FIG. 3; rather, it couldbe any other structure such as the full-bridge rectifying structure.

The control circuit 310 generates a control signal that is supplied tothe driver 320 for driving the primary side switch tubes S11, S12, andthe driver 330 for driving the secondary side switch tubes S21 to S24,so as to control the conduction or turning-off of each switch element(e.g., switch tubes S11, S12, S21 to S24) in the main circuit. Ofcourse, the control circuit 310 may further comprise other elementsnecessary for sampling, protection and communication; these elements ornot illustrated in the drawing, and hence will not be discussed indetail herein.

Since the power unit 120 is under the high-frequency operating status,and the output of the converter is a low-voltage high current,generally, the circuit composed of the secondary side of thetransformer, the output synchronous rectifying circuit and the outputcapacitor should be as small as possible so as to adapt for the need ofthe high frequency. Therefore, the transformer T1, the synchronousrectifying circuit (i.e., secondary side switch tubes S21, S22), theoutput capacitor C3 have to be disposed in a single unit circuit (i.e.,the power unit 120).

In one embodiment, the maximum operating voltage of the power supplyinput is greater than 20 V, the power unit 120 comprises: at least onetransformer T1, in which the transformer T1 comprises at least oneprimary side and at least one secondary side; at least one synchronousrectifying assembly (such as, the secondary side switch tubes S21, S22)and an output capacitor assembly (such as, the output capacitor C3). Thehigh frequency energy id delivered from the primary side to thesecondary side, and rectified by the synchronous rectifying assemblyinto a direct current, which is then transmitted to the output capacitorfor integration.

On the other hand, the peripheral of the control circuit 310 oftencomprises many peripheral circuits, and the signal required to beprocessed is low, and hence, they should be placed in proximity toincrease the anti-interference ability. Therefore, the control circuit310 and the peripheral circuits thereof should be placed in a singleunit circuit (i.e., the control unit 130). In one embodiment, thecontrol unit 130 is implemented by an embedding technique and thethickness thereof is less than 2 mm. The power unit (e.g., power supplyconverting circuit) is a resonant circuit with an operating frequencygreater than 1 MHZ. The control unit (e.g., control power supply) has aninput filter stacked thereabove.

Regarding the driver 320, 330, the primary side switch tubes S11 to S12,the resonant capacitor C2, and the resonant inductor L1 can be disposedin the power unit 120 or the control unit 130 depending on the actualneeds. The input capacitor C1 can inhibit the voltage peak of theprimary side switch tubes S11 to S12, and accordingly, it should bepreferably disposed with the primary side switch tubes S11, S12 in asingle unit. The L1/C2 can be obtained by integrating with otherelements such as the T1. Moreover, the T1 exciter inductor can be anindividual inductor that in parallel connection with the transformerprimary, so as to facilitate the optimization of the performance of theT1.

As illustrated in FIG. 1, the overall power circuit is formed bystacking the control unit 130 and the power unit 120, which willeffectively reduce the horizontal area of the power circuit 120; andhence, when the power circuit is placed on the main board 110, the spacethat it occupies on the main board 110 is reduced. In FIG. 1, thecontrol unit 130 or the power unit 120 can be manufactured by apackaging technique, e.g., using a plastic material in a moldingprocess, so as to form a module. Alternatively, the two units can bemanufactured as individual elements. Either way, each unit may comprisea bearing plate, such as, the printed circuit board (PCB) or the directbonding circuit (DBC), etc., for bearing the components of the unit;alternatively, the components can be directly stacked within the unit,for example, the switch element and elements such as the inductor andthe capacitor can be directly stacked with one another. When the primaryside switch tubes S11 to S12, the resonant capacitor C2, the resonantinductor L1 are integrated in the power unit, the circuit in the controlunit mainly handles the control signal, and hence, the height of thecontrol unit can be very small, such as less than 5 mm, 3 mm, or even 1mm.

In the case where the size of the power is bigger, it is possible toconnect several main circuits illustrated in FIG. 3 using the parallelconnection of the input/output. In this way, the overall structure ofthe power supply apparatus can use one main circuit as a power unit, andstacks several identical power units and a control unit, as illustratedin FIG. 1. The control unit 130 can be disposed at the lower positionwith two power units 120 stacking thereon, or the control unit can besandwiched between two power units, or the control unit can be placedabove the two power units. Either way, the structure takes fulladvantage of the height so as to achieve the goal of increasing thepower without changing the floor space. In this embodiment, the numberof the control unit 130 can be one, and it is configured to control theconduction and turning-off of the switch elements of the two power units120; or there can be multiple control units, for example, two, forrespectively controlling the conduction and turning-off of the switchelements of the two power units. Of course, it is possible to integratethe control unit and one of the power units, so that at least one powerunit 120 and one control unit 130 are stacked together, in which thecontrol unit is integrated from at least one main circuit. Asillustrated in FIG. 4. The power supply module comprises the power unit120 and the control unit 130 that are stacked together and areelectrically connected via the pins 140. In this embodiment, the powerunit 120 is integrated from an DC/DC converter, and the control unit 130is integrated from another DC/DC converter and a control circuit, inwhich the control circuit controls said two DC/DC converter.

As discussed above, the power supply apparatus receives an input,generates an output and provides the energy to the load. The powersupply apparatus may use the single-stage converter, such as the circuitillustrated in FIG. 3, to achieve the requirement for voltageconversion, or even isolation. Of course, multiple-stage converter canbe used. Due to the limitation of the characteristics of the component,usually, the single-stage circuit is not suitable for wide-rangeinput/output; hence, for a load with a wide voltage range, such as theCPU, memory and other loads applied in the server power supply, it ismore appropriate to use a two-stage power supply; in this case, one ofthe which is responsible for isolation, while another one is responsiblefor voltage adjustment; each responsible for its own function so as toachieve the optimal performance. For example, structure like this isillustrated in FIG. 5 or FIG. 6.

As illustrated in FIG. 5, the input voltage Vin is a wide voltage range,such as 38 to 60 V, the input voltage uses a front-stage circuit (suchas an isolated non-regulated DC/DC converter; i.e., an isolatedtransforming module DCX; as used herein, the term “non-regulated” meansthat the input/output of a circuit in the operating range is fixed at aconstant ratio; that is, the output varies in proportion to the input,such as Vin/Vo=n; for example, in FIG. 5, Vin/Vo=4) to achievehigh-voltage isolation; and then uses a post-stage circuit (such as anon-isolated regulated DC/DC converter) to provide the output to theload. For example, the post-stage circuit could be a point-of-load (POL)converting unit that could be used to fulfill the needs for outputtingstabilized voltage and dynamic response. Since the post-stage circuithas the adjusting capability, and therefore, the front-stage circuitdoesn't need to have the adjusting capability. However, if needed thefront-stage circuit may have the full or partial adjusting capability;for example, the front-stage circuit can be an isolated DC/DC converter.

Referring to both FIG. 1 and FIG. 5, the two power units 120 canrespectively be a power unit of the primary DC/DC converter and thepower unit of the secondary DC/DC converter; the control unit 130comprises the control unit of the primary DC/DC converter and thecontrol unit of the secondary DC/DC converter. Specifically, the primaryDC/DC converter is an isolated DC/DC converter; secondary DC/DCconverter is a non-isolated regulated DC/DC converter (such as the oneillustrated in FIG. 5), the non-isolated regulated DC/DC converter iscloser to the main board 110 than the isolated DC/DC converter is.Alternatively, the primary DC/DC converter is a non-isolated regulatedDC/DC converter; the secondary DC/DC converter is an isolatednon-regulated DC/DC converter. For example, the primary DC/DC converteris a buck-boost circuit.

In one embodiment, the power unit 120 is a primary DC/DC converter; thecontrol unit 130 is a power unit of a secondary DC/DC converter. Forexample, the primary DC/DC converter is a non-isolated regulatedconverter; the secondary DC/DC converter is a non-regulated isolatedconverter; or, the primary DC/DC converter is an isolated converter; thesecondary DC/DC converter is a non-isolated regulated converter.

Since the front-stage circuit is a non-regulated isolated transformingmodule DCX, it is possible to design it so that the circuit operates atthe optimal operating point, thereby making the circuit relativelysimple with a high efficiency. When the isolated transforming module DCXis a resonant circuit, the isolated transforming module DCX may operatearound the resonant frequency; and when the DC transformer DCX is a PWMcircuit, such as a full-bridge circuit, it can operate under thecondition with the greatest mark-space ratio. The post-stage circuit isa regulated circuit, such as a point-of-load (POL) DC converter which isusually implemented by a buck circuit (such as, POL buck DC converter),so that the characteristics of the output fulfills the requirement ofthe load; in this case, the circuit is simple, and the output voltagerange is quite wide. Combining the two, it will be easy to achieve therequirements of wide input/output voltage range, high output voltageaccuracy, and dynamic response property. When the isolated transformingmodule DCX uses the resonant circuit, such as the LLC-SRC circuit, it iseasier to achieve a power supply with high efficiency and high powerdensity under high frequency. Of course, since the post-stage circuithas the regulation capability, if the DCX reduces the voltage-withstandvalue of the intermediate BUS capacitor and associated power component,due to certain reason, such as the reduction of the intermediate BUSvoltage range, so that the DCX has certain level of output voltageregulation capability, it will not affect the implementation andfunction of the present invention.

As illustrated in FIG. 6, the input voltage Vin is a wide voltage range,such as 38 to 60 V. The input voltage Vin uses a front-stage circuit(such as a non-isolated regulated DC converter; i.e., a front regulatemodule (FRM)) to convert the input voltage into a desired value, such asa constant voltage of 48V, and to respond to the dynamic change of theload; and an isolated non-regulated DC converter (i.e., an isolatedtransforming module DCX) is connected thereafter in parallel connectionto achieve the voltage isolation, and the requirement for bucking. Underthis structure, the stabilized voltage and dynamic response of the finaloutput (i.e., the output of the post-stage circuit) are implemented bythe front-stage circuit. Since the front regulate module (FRM) does notrequire isolation, it could be implemented with various topologies, suchas, buck, boost or buck-boost circuit; for high frequency application,it is possible to implement the soft switching technique. Therefore, thefront regulate module (FRM) may have a very high power density, and sodoes the isolated transforming module DCX.

Referring to both FIG. 1 and FIG. 6, one power unit 120 of the two powerunits 120 comprises the power unit of the primary DC/DC converter andthe power unit of the secondary DC/DC converter; the primary DC/DCconverter is an isolated non-regulated DC/DC converter, while thesecondary DC/DC converter is a non-isolated regulated DC converter (asillustrated in FIG. 6).

Using the above-discussed two power supply structures, take main boardpower supply with the output power of 200 W as an example, it ispossible to implement the isolated transforming module DCX andpoint-of-load (POL) DC converter (the structure of FIG. 5) or the frontregulate module (FRM) and isolated transforming module DCX (thestructure of FIG. 6) within a floor space of 1/16 brick (1.3 in*0.9 in,or 33 mm*22.9 mm); therefore, the power pressure is 85.5 W/inch² (infact, due to the installation space required between two units, thepower pressure is even lower). Since the height of the two units is lessthan 10 mm or even 7 mm, if the two units are stacked according to themethod provided by the present disclosure (as illustrated in FIG. 7),the control unit and the power unit are integrated as an isolatedtransforming module DCX which is stacked with the point-of-load (POL) DCconverter on the main board 110; or, as illustrated in FIG. 8, thecontrol unit and the power unit are integrated as a front regulatemodule (FRM) which is stacked with an isolated transforming module DCXon the main board 110. In this way, the power pressure can beimmediately doubled to 171 W/inch², thereby greatly reducing therequired space on the main board. Even though the stacking may requiresome additional height for reasons such as heat dissipation, the overallheight thereof can be less than 25 mm, which fully complies with therequirement for the height of the server (which could be as high as 30mm).

To reduce the volume occupied by the pins for interconnection, the powerstages of the above-mentioned isolated transforming module DCX andpoint-of-load (POL) DC converter can be manufactured in a single powerunit 120, and the control circuits of two stages are manufactured in asingle control unit 130. In this way, the handle of the power parts canbe centralized, so as to achieve a better efficiency and smaller floorspace. Depending on actual needs, said power unit part, can be one partsor multiple parts in parallel connection, as illustrated in FIG. 9;multiple power units 120 are in parallel connection and each comprisesthe power stages of an isolated transforming module DCX andpoint-of-load (POL) DC converter, the control unit 130 comprises thecontrol circuits of the isolated transforming module DCX andpoint-of-load (POL) DC converter.

FIG. 11 illustrates the principle of the circuit structure of FIG. 5.FIG. 11 differs from FIG. 3 in that it has an additional post-stagecircuit—the circuit of the circuit point-of-load (POL) DC converter,such as the buck circuit illustrated in FIG. 11, in addition to theparts illustrated FIG. 3. Since the output is a low-voltage highcurrent, the POL is usually implemented using several buck circuits inparallel connection. The specific number of the circuits in parallelconnection depends on the actual condition. For example, in FIG. 11,there buck circuits are in parallel connection. The isolatednon-regulated DC/DC converter comprises: an isolated transformer T1, aplurality of primary switch tube S11, S12 and a plurality of secondaryswitch tubes S21, S22; the non-isolated regulated DC converter is apoint-of-load (POL) DC converter. The circuit of each point-of-load(POL) DC converter respectively comprises the switch tubes S31, S32 andS33 and filtering inductors L21, L22 and L23 and connected with theswitch circuits, which form the corresponding buck circuit. The outputof the circuit in each point-of-load (POL) DC converter is in parallelconnection with the two terminals of the capacitor C4, so as to generatethe output power and provided the same to the load. The control chip1100 is configured to generate the control signal for controlling theconduction and turning-off of the switch elements in the point-of-load(POL) DC converter. To achieve a high efficiency, the power unit 120comprises the isolated transformer T1, the synchronous rectifying switchtubes S21 to S24, and the output capacitor C3 of the isolatedtransforming module DCX, and the switch tubes S31 to S33 of thepoint-of-load (POL) DC converter. In other words, the isolatedtransformer T1, the secondary switch tubes S21, S22, S23, S24, theoutput capacitor C3 for isolating the DC/DC converter, and thepoint-of-load (POL) DC converter are disposed within a single power unit120. Of course, the structure in FIG. 11 further comprises the filteringinductors L21 to L23 and the output capacitor C4. The control unit 130comprises a control chip 1100 and the peripheral circuit thereof, suchas the signal processor DSP illustrated in FIG. 11 and the peripheralcircuit of the controller (not shown). The primary switch tubes S11, S12are disposed in the control unit 130, and the control unit 130 furthercomprises the primary switch tube driving circuit, the control drivingcircuit of the POL DC converter, and the control chip 1100.

The structure for the front regulate module (FRM) and isolatedtransforming module DCX can also be implemented in this way, so as toachieve both the higher efficiency and higher power pressure; asillustrated in FIG. 10, multiple power units 120 are in parallelconnection, and each of which comprises the power stages of the frontregulate module (FRM) and the isolated transforming module DCX; thecontrol unit 130 comprises the control circuits of the front regulatemodule (FRM) and the isolated transforming module DCX.

Of course, the above-mentioned isolated transforming module DCX can alsobe a regulated converter or semi-regulated converter. The variation infunction will not affect its contribution to the improvement of theefficiency and the power pressure.

In the above embodiments, all of the power supplies use the DC to DC(DC/DC) converter. These embodiments can be applied in structures suchas where the DC power supply directly inputs to the server main board.Of course, with the advancement of the technology, there might be thecase where the AC power supply AC directly inputs to the server mainboard 1200. As illustrated in FIG. 12, the AC power supply AC (such as220 Vin) directly connects to the server main board 1200, and providesthe input power to the corresponding load through the main board powersupply 1210 composed of cascaded or parallel-connected power supplymodules 1201 to 1205. In comparison to the above-mentioned main boardpower supply of the DC input, this structure further comprisesfront-stage cascaded electromagnetic interference (EMI) filter 1221, thepower factor correction (PFC) circuit 1222 and the auxiliary powermodule 1223, etc. In this structure, the above-mentioned stackingtechniques can also be used.

FIG. 13 is a schematic diagram illustrating a EMI filter 1310 cascadedwith a post-stage PFC circuit 1320. As illustrated in FIG. 13, after theEMI filter 1310 receives the AC input, e.g., V_(AC)=220 V, it providesan output signal to the post-stage cascaded PFC circuit for power factorcorrection. In practice, the PFC circuit 1320 can be implemented invarious topologies, such as the boost, buck, dual-boost and the totempole structure illustrated in FIG. 13. Take the totem pole PFC circuitillustrated in FIG. 13 as an example, the main circuit in the PFCcircuit 1320 comprises a high frequency capacitor C, a PFC inductor Land power switch devices (that is, a first bridge-arm composed ofserially connected active switching elements S1, S2, and a secondbridge-arm composed of serially connected passive switch elements D1,D2). The first and second bridge-arms and the high frequency capacitor Care in parallel connection; the power switch devices and the highfrequency capacitor C are electrically coupled to the PFC inductor L;two middle points of the two bridge-arms are respectively connected withthe output of the EMI filter 1310 or are connected with the output ofthe filter via the input inductor. The corresponding driving and controlcircuit 1330 of the PFC is configured to control the power switchdevices; specifically, the corresponding driving and control circuit1330 of the PFC comprises an output sampling voltage divider 1331 thatis configured to sample the output V_(DC) of the PFC main circuit; inputsampling voltage dividers 1332, 1333, 1334 are configured to sample theinput voltage V_(AC-P) and V_(AC-N), and a sampling circuit for samplingthe input current I_(L). After being compared with the correspondingreference signal V_(DC-ref), the output signal V_(DC) of the outputvoltage sampling voltage divider 1335 is outputted by a voltage loopcontroller 1335 as a signal, which is calculated with the V_(AC) toobtain a reference signal I_(L-ref) of the input current I_(L); afterthe input current I_(L) is calculated and compared with the I_(L-ref),it passes a current loop controller 1336 to obtain a correspondingcontrol signal PWM-S1 and PWM-S2 for controlling the switches S1 and S2.

The present disclosure is also suitable to be used in the DC/AC setting,such as the inverter. FIG. 14 illustrates a power unit 120 comprising aninverter circuit; the DC input Vin passes a first bridge-arm composed ofserially-connected active switching elements S1, S2 and a secondbridge-arm composed of serially-connected active switching elements S3,S4 to give an AC signal; the signal passes a filtering circuit(comprising a filtering inductor L and an output capacitor Co) and thengenerates an output voltage Vo on the output capacitor Co. The specificcontrol and driving circuit is not shown herein. Such inverter can alsoadopt a stacking structure that is similar to those described aboveregarding the PFC circuit. That is, the control unit is integrated fromthe first and second bridge-arms, the input capacitor Cin and thecontrol driving circuit of the main circuit, while the power unit isintegrated from the output filtering inductor L and the output capacitorCo. Of course, it is also feasible to integrate all elements of the maincircuit (i.e., the output capacitor Cin, the S1 to S4, the filteringinductor L and the output capacitor Co) to form the power unit 120, andintegrate the control unit to form the control and driving circuit.

Examples of Control Unit

The main purpose of the control unit is signal processing, and theheight of most components thereof is smaller; hence, to improve theoverall utilization percentage of the space, it is possible to use thethinness of the elements comprised in the unit as an evaluation index.

As discussed hereinabove, the controller (under certain specificapplication, the driving circuit can be viewed as part of thecontroller) responsible for sending the signal to the driving circuit orswitch devices and elements necessary to the peripheral circuit thereof(such as the resistor, capacitor, etc.) must be comprised in the controlunit. However, with the improvement of the integration level of thecontrol chip, after these components/elements are disposed, there mightbe certain space left thereon. Accordingly, it is possible to add morecomponents/elements in the control unit. Take FIG. 3 as an example; ifall the power components are disposed in the power unit 120, the layoutof these components is illustrated in FIG. 15. In FIG. 15, the left-handside illustrates the layout of the components/elements of the power unit120, and the right-hand side illustrates the layout of thecomponents/elements of the control unit 130. In FIG. 15, the square boxindicates the bearing plates 1710, 1720 on which the components/elementsare placed; as to the components/elements disposed on the bearing plate1710, 1720, those illustrated in the left-hand side correspond tocomponents/elements illustrated in FIG. 3. As illustrated in FIG. 15, ifthe area of the power unit 120 and the area of the control unit 130 arethe same (that is, the areas of the bearing plates 1710, 1720 of the twounits are the same), apparently, the utilization percentage of thecontrol unit 130 is low. To increase the utilization percentage of thearea of each unit, it is feasible to move some components/elements fromthe power unit to the control unit 130; as illustrated in FIG. 16, theprimary switch tube S11, S12 is disposed at a position in adjacent tothe lateral side of the control unit (i.e., they are disposed on thebearing plate 1720 of the control unit 130. In addition to the thinness,the standard for selecting the components/elements to be moved alsoincludes whether it will affect the electric characteristics and whetherit will achieve better functions.

The primary side switch tubes S11, S12 at the high-voltage input sideare semiconductors, as such, the thickness thereof is similar to or eventhinner than the control chip, and hence, they could be placed in thecontrol unit. For example, when the switch tubes S11 and S12 at theprimary side are MOSFETs, if they are placed in the power unit, asillustrated in FIG. 3, there are more than 4 pins (the gate electrodeand source electrode for each switch) for the interconnection of thepower unit 120 and control unit 130; if they are placed in the controlunit 130, there is only two pins for the interconnection of the controlunit 130 and the power unit, such as the connection point of the switchtubes S11 and S12 at the primary side and the source electrode of theswitch tube S12, as illustrated in FIG. 11. Moreover, since thehigh-voltage input side is not particularly sensitive to thedistribution parameter of the circuits, the effect to the electriccharacteristics resulted from moving them to the control unit 130 iswithin the acceptable range. Of course, if the switch tubes S11 and S12at the primary side are moved, the input capacitor C1 and the drivingcircuit thereof should also be moved to the control unit 130. Puttingthese elements in close proximity will not only reduce the voltage peakof the switch tubes S11 and S12 at the primary side, but also reduceunnecessary pins in the power unit.

FIG. 16 is a schematic diagram illustrating an embodiment where some ofthe switch devices are disposed in the control unit 130. The controlunit 130 comprises an input capacitor C1, the resonant capacitor C2 andthe primary side switch tubes S11, S12; the power unit 120 comprises aplurality of switch devices and a bearing plate 1710 for bearing theswitch devices (such as, S11, S12), as well as an insulation material3430 (illustrated in FIG. 25) for encapsulating the switch devices; theswitch devices are distributed at a position along the pads 3440(illustrated in FIG. 25). The power unit 120 comprises a transformer T1,a resonant inductor L1, an output capacitor C3 and secondary side switchtubes S21, S22, S23, S24. As could be seen, the utilization percentageof the left-hand side of the control unit 130 is significantlyincreased, while the inductor (i.e., the resonant inductor L1), thecapacitor (i.e., the output capacitor C3) and switch devices (i.e.,secondary side switch tubes S21, S22, S23, S24) are disposed at aposition on the bearing plate 1710 in adjacent to the lateral side ofthe power unit. On the left-hand side of the power unit 120, more spaceis left for the magnetic element, which is significant to the increaseof the efficiency. Accordingly, embodiments of the present disclosuremay take care of both the high efficiency and high power pressure. Itshould be noted that since the switch tubes S11, S12 are not disposed inthe power unit 120, the input of the power unit 120 comes from thecontrol unit 130, and is a high frequency AC power signal modulated bythe switch tubes S11, S12; for example the frequency of the signal isabout 500 KHZ or even higher than 3 MHZ, and the value may be less than12 V to more than 400 V.

If, in certain applications, the positions of the secondary side switchtubes S21, S22, S23, S24 are not sensitive to the electriccharacteristics, it is also possible to dispose the secondary sideswitch tubes S21, S22, S23, S24, the driver 330 and the output capacitorC3, as well as the Oring MOS in the control unit 130 so as to furtherincrease the space utilization percentage.

Regarding the stacking structure illustrated in FIG. 10, if the controlunit 130 is disposed at the lower position, the control unit 130 will besandwiched between the power unit 120 and the main board 110; then thepins from the output terminal of the power unit 120 to the main boardbecome longer, which might affect its ability to response to thevariation of load, in particularly in cases where the load is a dataprocessing chip like the CPU. In this case, it is possible to disposepart of the output capacitor C3 (or the corresponding POL outputcapacitor C4 illustrated in FIG. 11) of the main circuit in the controlunit 130; in this case, the control unit 130 comprises the outputcapacitor C3, thereby reducing the effect resulted from the length ofthe pins. Of course, to do this, it is a requisite that there is a goodconnection between part of the output capacitor C3 and pins 140.

In the above-mentioned embodiments, the control unit 130 comprises abearing plate, such as the printed circuit board or the lead frame, etc.Of course, the whole control unit 130 can be implemented by an embeddingtechnique. The control unit 130 can also uses inter-stacking elementswithin the unit, so that the surface conductors of the elements are usedfor electric connection. Using the embedding technique, some electricelements, such as the control IC, the resistor, the capacitor and eventhe power semiconductor are embedded in the bearing plate. In this way,the control unit is very thin and the area thereof is very small; also,a more delicate circuit wiring at the internal and surface of the unitcan be achieved. By using the embedding techniques, one can easilyachieve the interconnection between the upper and lower surfaces withoutlimited by the position; that is, it can directly use the correspondingpins without using the pins injected from the lateral side, which isillustrated in FIG. 25. For example, a circuit comprising a transformerand a synchronous rectifier, such as a bridge resonant circuit, can beused to implement a control unit using the embedding technique then, thecontrol unit is stacked with a power module comprising the transformerand synchronous rectifier, and the resultant circuit is characterized inthat: the power unit comprises at least one transformer (Core andWinding), the output synchronous rectifier, part of the outputcapacitor, the control signal of the SR MOS (generated by the powermodule or provided by the control unit), so as to achieve a highefficiency of the power stage; the power unit still uses the pins (Pin)injected from the lateral side, the Pin comprises the positive andnegative electrodes of the output, and the two electrodes of the highfrequency pulse at the input side that has been modulated. The controlunit comprises an embedded control logic IC, responsible for sampling,controlling signal and driving the signal generation, protecting, andnecessary communication to the outside of the power supply, as well asat least one pair of power elements at the high-voltage side,responsible for generating the input-side high frequency pulse to betransmitted to the power unit; the pins of the control unit can bearranged at the lateral side or passing through the upper or lowersurface, depending on the need, or can be arranged to form theconnection from the internal position to the surface and arranged at thesurface as needed; after the embedding, the control unit is very thin,e.g., about 1 mm; accordingly, the Pins can be mainly the SMD pins, soas to enhance the connection strength of the Pins. By using theembedding technique, one can easily achieve the wiring capabilitysimilar to the PCB, so as to implement more complex interconnection atthe surface, and support the stacking combination with more content, forexample, disposing some necessary elements that is difficult to beembedded in the control unit, e.g., the input EMI filter (i.e., theinput capacitor) together with the power unit at the surface of thecontrol unit. This embodiment achieve a very small size, and hence, itis more suitable in high-frequency operating settings, such as the onewith an operation frequency of more than 1 MHZ. Hence, the convertingcircuit is preferably a resonant-type circuit. The thickness of theembedded-type control unit is preferably less than 2 mm.

The control unit 130 can be the assembly of the control circuitsaccording to the above-mentioned examples, can be a control circuitcomprising some components/elements of the power circuit, and even thedriving circuit; alternatively, it can also be a power supply converterwith full function, such as the one as illustrated in FIG. 7. In thisway, the control unit and the power unit are stacked together, andconnected through pins, as well as connected to the main board throughthe pins, thereby achieving a structure with two or more inter-stackingpower units. Nonetheless, at least one of the power units comprises thecomponents/elements of the control unit. Such structure is oftensuitable for use in a system infrastructure with multi-stage power unitin parallel connection or cascaded connection.

Examples of Power Unit

In sum, the power unit can be a complete DC/DC or AC/DC power supplyconverter that can operate on its own, such as, the isolatedtransforming module DCX, the point-of-load (POL) DC converter, the frontregulate module (FRM), the regulated bus converter (RBC), the PFCcircuit, the auxiliary power supply module, etc.; that is, one powersupply converter that comprises the power stage circuit and the controlcircuit; alternatively, it could be only the power stage circuitthereof, or even a portion of the power stage circuit such as thosedescribed in the above embodiments; said portion can be the part thatshould be placed in proximity, such as the three key elementsillustrated in FIG. 16, that is, the transformer T1, the outputrectifying element (e.g., the secondary side switch tubes S21, S22, S23,S24) and the output capacitor C3. The power unit may have the isolationcapability of the isolated transforming module DCX, RBC; that is, itcomprises at least one transformer; or it may not require the isolation,like the point-of-load (POL) DC converter, the front regulate module(FRM), and the PFC circuit; that is, it comprises at least one inductor.

The transformer and inductor on the power unit can be integrated orseparated.

The input of the power unit can be a direct current or anindustrial-frequency alternating current, or the high-frequencyalternating current illustrated in FIG. 16.

The output of the power unit can be within various voltage ranges, suchas 0.1 to 12 V, or 12 V to 400 V. The load can be another power supplyconverter, the hard drive, the memory, the graphic processing chip, theCPU, the communication ASIC, or other data processing chips.

Moreover, the power unit, just like the control unit, may comprise abearing plate, such as the printed circuit board or the lead frame, andthe electric connection among the components of the power unit isachieved by the trace on the bearing plate, the components/elements ofthe power unit can also be placed on the bearing plate; or can beimplemented by the embedding technique; that is, the electric element,such as the transistor and the capacitor are embedded in the bearingplate. Moreover, the power unit can also uses inter-stacking elementswithin the unit, so that the surface conductors of the elements are usedfor electric connection.

When the whole circuit comprises two or more power units, it is possibleto use identical power units that are in parallel connection toimplement a conversion of higher power and higher current; or they canbe serially connected to implement a conversion of higher power andhigher voltage; alternatively, different power units that are seriallyconnected (as illustrated in FIG. 8) are used to achieve a greateroperating range; or different power units can be used, in which theyshare a common input to provide the power supply conversion of multipleoutputs; or different power units can be so that one output can receivethe power supply conversion from multiple inputs.

In view of the foregoing, the application range of the presentdisclosure is quite broad; it may enhance the performance of the server.Of course, the method for implementing the power converter is alsosuitable for use in other application settings.

Design of Stack Structure

In one aspect of the present invention, in one server, a power supplyconverter is divided into at least two units, i.e., at least one controlunit 130 and one power unit 120, that are stacked to take full advantageof the height, thereby providing a power supply converter with highefficiency and high power pressure, so as to provide a server withbetter performance. The stacking of the power supply converter are asfollows.

As illustrated in FIG. 17, the unit with a greater area among thecontrol unit and the power unit is used as the first unit 2010, whilethe one with the smaller area is used as the second unit 2020; the firstunit 2010 is disposed between the second unit 2020 and the main board110; the area of each unit 2010, 2020 differs, and the smaller one isstacked on the bigger one to form a power supply converter which is thendisposed on the main board 110. As illustrated in FIG. 18, the controlunit and the power unit are integrated as an isolated transformingmodule DCX, and front regulate module (FRM); this is one implementationof the above-mentioned front regulate module (FRM)+isolated transformingmodule DCX infrastructure; however, to achieve a higher efficiency, theexternal inductor L of the front regulate module (FRM) is disposedoutside. The front regulate module (FRM) and the external inductor L arethen disposed above the isolated transforming module DCX to form a powersupply converter, which is then disposed on the main board 110.

As illustrated in FIG. 19, the unit with a greater area among thecontrol unit and the power unit is used as the first unit 2010, whilethe one with the smaller area is used as the second unit 2020; thesecond unit 2020 is disposed between the first unit 2010 and the mainboard 110; the area of each unit 2010, 2020 differs, and the smaller oneis stacked at the lower surface of the bigger one to form a power supplyconverter which is then disposed on the main board 110.

As illustrated in FIG. 20, the power unit 120 and the load are disposedat one side of the main board 110, while the control unit 130 isdisposed on the main board 110 at a side that is opposite to the powerunit 120; the power unit 120 and the control unit 130 are respectivelydisposed at the opposite surfaces of the main board 110; that is, eachunit 120, 130 is respectively disposed at the upper and lower surfacesof the main board 110; the control unit 130 is electrically connected tothe pins 140 via the conducting through holes 2310 of the main board110; the overlapping part of the projection areas of the units accountsfor at least one-third of the projection area of said unit. Apparently,due to the limitation of dissipation and the thickness, it is preferablythat the control unit 130 is disposed at the lower surface of the mainboard, and the power unit 120 is disposed at the upper surface of themain board 110.

Obviously, the above-mentioned implementation means can effectivelyutilize the height, so as to achieve both the high efficiency and highpower pressure of the power supply, to give a power supply module withbetter performance, especially in applications such as the server powersupply.

Pads Arrangement and Implementation

A power supply converter comprises many pins. Pins involved in theconnection between the converter and the system include, for example,converter power input/output pins, and pins for system communication,and pins for internal interconnection, such as the connection betweenthe power unit and the control unit. Since the terms pins has a specificdefinition, here, the pins injected from the components/elements on thebearing plate is referred to as the pads. Referring to FIG. 21, the padscan be divided into two main types, the power pads and the signal pads,depending on the current level. The power pads are the pads that theconverter power current passes pads, which is generally responsible forthe electric connection between components/elements of the powercircuit; since the current level passing them is higher, these pads areoften thicker; that is, the cross-sectional area of the pad is bigger.The signal pads are the pads responsible for transmitting the signal inthe converter; for example, the control circuit in the control unitoften transmits the control signal to the driving circuit through thesignal pads so as to control the conduction and turning-off of the powercomponents/elements. Generally, the current level passing throughcontrol pads is lower, and hence, the pads are thinner; that is, thecross-sectional area thereof should not be too big, and the size oftendepends on the capability required.

When the power supply converter is an isolated circuit (the isolation isoften achieved by the transformer of the power circuit); that is, theinput/output thereof has the requirement of isolated safety voltage.Hence, depending on the position thereof, the pads can divided as theprimary lateral group pads (i.e., the pads disposed at the primary sideof the transformer) and secondary lateral group pads (i.e., the padsdisposed at the secondary side of the transformer). The two groups ofpads should be separated by a specific distance to meet the safetyrequirement; for example, when the input of the converter is 400 V, anisolation of at least 2000 V is required and hence, any pads in onegroup should be separated from any pads in the other groups by at least4 to 8 mm; while when the input is 36 to 72 V, an safety isolationvoltage of 1500 V is often required, and the distance is 1 to 4 mm.Regarding the primary lateral group, since the voltage of the input isrelatively high, the current is smaller, and the cross-sectional area ofsuch pads is relatively small. For the secondary lateral group, sincethe voltage is lower, the current is higher, and hence, thecross-sectional area of the pads is greater. For example, for the 48 Vto 1 V converter, the difference of the current is 48 folds, if the samecurrent density is used to define the volume of the pads, there would bea 48-fold difference, and it is obvious that the secondary lateral grouprequires more position for the disposition.

The pads can be disposed at the four sides of the power unit, asillustrated in FIG. 21 and FIG. 22. In FIG. 21, the primary lateralgroup pads 2410 and the secondary lateral group pads 2420 respectivelyoccupy the two sides of the power unit, and said two sides are parallelto each other; the primary lateral group pads 2410 comprises firstsignal pads 2411 and first power pads 2412, the cross-sectional area ofthe first power pads 2412 is greater than the cross-sectional area ofthe first signal pads 2411; the secondary lateral group pads 2420comprises second signal pads 2421 and second power pads 2422, thecross-sectional area of the second power pads 2422 is greater than thecross-sectional area of the second signal pads 2421, the number of thesecond power pads 2422 is greater than the number of the first powerpads 2412. The arrangement in FIG. 21 is suitable for applications withlower output current. FIG. 22, on the other hand, is suitable for use inapplication with higher current output; the primary lateral group pads2410 are distributed along one side of the unit, and the secondarylateral group pads 2420 are distributed along the remaining three sidesof the unit, and are spaced from the primary lateral group pads 2410 bya safety distance d. When the current is higher, a single pad has agreat electrical characteristics; when multiple pads are required, i.e.multiplex pads, they can be arranged in alternating positive andnegative electrodes, such as, Vo+, Vo−, so that the induction resistanceof the pads is as low as possible; in this way, when applied in loadslike CPU, there is a better dynamic response and reduce the utilizationrate of the capacitor of the main board.

In the present application, the pins are electrically coupled with thepads. FIG. 24 is a front view illustrating the connection of the pinsand pads for implementing the interconnection of each unit. In FIG. 24,the exemplified pins are surface-mount pins. The L-shaped surface-mountpins 2610 electrically connects each unit 120, 130 to form a powersupply converter with the surface-mount pins, which is then disposed onthe main board 110. After changing the pins to the I-shaped pins, thepower supply converter with the I-shaped in-line pins 2710 (asillustrated in FIG. 23) is formed.

FIG. 25

Before the assembly of the pins 140, each unit 120, 130 can beencapsulated with the packaging technique such as molding or embeddingto for a regular surface, such as the recess 3410 illustrated in FIG.25; since the insulation material 3430 has the recess 3410 disposedthereon for fitting the installation of the pins 140, it is moreadvantageous to the delicate utilization of the space, and then thesurface-mount pins are installed thereon. Specifically, any one of thecontrol unit and the power unit comprises a bearing plate 3420 andinsulation material 3430; the insulation material 3430 is formed on thetwo opposite surfaces of the bearing plate 3420 l the lateral side ofthe bearing plate 3420 is disposed with the pads 3440; the solderingmaterial 3450 on the pads 3440 is soldered to the pins 140. At the edgeof the upper and lower surface of the insulation material 3430, there isa recess 3410; the two terminals of each pin 140 has the SMD pad 2910extending to the recess 3410 at the upper and lower surfaces, the recess3410 has the bonding material 3460 disposed thereon for bonding with theSMD pads 2910.

The unit illustrated in FIG. 25 can be any of the above-mentioned powerunit and/or control unit; the pads 3440 are distributed along thelateral side of the power unit and the lateral side of the control unit;the pins 140 and pads 3440 are electrically coupled. The pins 140 aresurface-mount pins, and are distributed along the outer surface of thepower unit and control unit, and are electrically coupled to the pads3440. The pads 3440′ are further distributed along a side of the powerunit that is perpendicular to the side at which the and pads 3440 aredisposed; although in FIG. 25, the pads 3440′ are only distributed alongthe lower surface; the present invention is not limited thereto; in oneembodiment, pads are distributed along the lateral side of the powerunit 120 and the upper and lower surfaces of the control unit 130, andthe pins 140 and pads 3440 are electrically coupled.

The surface-mount pins can be installed on each surface of the unit, butin order to achieve a better dissipation effect and to further reducethe overall size of the module, in the above examples, the pads aredisposed at the lateral side of the bearing plate in each unit, and thesurface-mount pins are soldered to connect with in injected pins of thecomponents of the unit and the control signal injected pins. However,under certain special circumstances, as illustrated in FIG. 33, the padsin the first unit 2010 can also be disposed at the stacking surface ofthe second unit 2020 and the inductor L, and the pins are used toimplement the typical connection between the first unit 2010 and thesecond unit 2020 and the inductor L. The contact surface other than thesolder points of the pins and pads can be applied with glues or thelike, so that the pins are bonded to the surface of each unit, therebyincreasing the mechanical strength and the reliability.

Heat Dissipation

After stacking each unit to form a module, the heat dissipation pathwayis altered, as compared with the conventional design in which the unitsare individually disposed.

FIG. 26 illustrates the installation of the heat dissipation unit. Asillustrated in FIG. 26, the electrically-isolated heat dissipation unit3910 is disposed on the power unit 120; the power unit 120 is disposedon the control unit 130; the control unit 130 is disposed on the mainboard 110; or, as illustrated in FIG. 40, the electrically-isolated heatdissipation unit 4010 is disposed on the lateral sides of the power unit120 and the control unit 130. It can be disposed at the upper surface orthe lateral side of the assembled module. To avoid affecting theelectric characteristics of the module, the heat dissipation unit can bean electric insulation material, such as the ceramic. Alternatively,when the heat dissipation unit is a conducting material such asaluminum, copper, graphite, etc., thereby should be a thermal-conductingand electrical-insulation material (such as the ceramic sheet or thelike) between the heat dissipation unit and the pins. The heatdissipation units are all disposed above the pad or pin assembly. Toensure the heat dissipation effect, the thermal resistance between theheat dissipation unit and the pad or pin assembly should be less than 5°C./Watt. There is an insulation material between the heat dissipationunit and the pad or pin assembly.

Other Optimized Embodiments

According to the above-mentioned example, it is feasible to achieve agreater power by stacking multiple power units. Generally, these powerunits use the magnetic elements with the similar using/operatingcondition, such as a transformer or an inductor.

As illustrated in FIG. 43, since the magnetic element often has an airspace 4320, and the conductor nearby is often inducted and heated by themagnetic flux leaked from the air space 4320, thereby causing loss. Bysharing the magnetic core 4310 through stacking, the air space 4320 ofthe magnetic core 4310 can be disposed at the stacking space 4330between the power units 120, thereby keeping the air space from theconductor so as to reduce the loss.

According to the above-mentioned embodiments, the power unit and thecontrol unit are vertically stacked to form a power supply module. Infact, if the power supply is rotated by 90 degrees so that the powerunit and the control unit are stacked horizontally, and areinterconnected with each other and are respectively connected with themain board through the pins, this structure also has desirableapplicability. Therefore, according to embodiments of the presentdisclosure, the power unit and the control unit can not only stack aboveeach other, but also stack to the left or right of each other in thehorizontal direction.

In view of the foregoing, using the Quasi-Cascade components, optimizeddriving, optimized application and optimized packaging disclosed herein,it is possible to increase the power density or efficiency of the powersupply converter, thereby achieving a better electric performance,higher frequency performance and greater reliability, as compared withconventional technology. In this way, the characteristics of thecomponents can be fully utilized, and it is more convenient to use theapparatus with the present packaging solution; therefore, the presentdisclosure facilitate the improvement of the power density orefficiency. The specific driving, application and packaging meansprovided by the present disclosure are quite feasible and effective. Thepresent invention is suitable for improving the overall performance andthe cost/performance ratio of the power supply converter.

Although various embodiments of the invention have been described abovewith a certain degree of particularity, or with reference to one or moreindividual embodiments, they are not limiting to the scope of thepresent disclosure. Those with ordinary skill in the art could makenumerous alterations to the disclosed embodiments without departing fromthe spirit or scope of this invention. Accordingly, the protection scopeof the present disclosure shall be defined by the accompany claims.

What is claimed is:
 1. A power supply apparatus, comprising: a bearingplate; insulation material formed on two opposite surfaces of thebearing plate; and a plurality of pins electrically connected to thebearing plate and allocated along lateral sides of the insulationmaterial.
 2. The power supply apparatus of claim 1, further comprising:a plurality of first pads disposed on lateral sides of the bearingplate.
 3. The power supply apparatus of claim 2, wherein the pluralityof pins are electrically connected to the plurality of first pads, andthe plurality of first pads are electrically connected to the bearingplate.
 4. The power supply apparatus of claim 3, wherein two terminalsof each of the pins have two SMD pads, wherein the two SMD pads of eachof the pins are extending to an upper surface and a lower surface of theinsulation material, respectively.
 5. The power supply apparatus ofclaim 4, wherein edges of the upper surface and the lower surface of theinsulation material have recesses, and the two SMD pads of each of thepins extend to the recesses at the upper surface and the lower surfaceof the insulation material.
 6. The power supply apparatus of claim 2,further comprising: at least one second pad, wherein the second pad islocated at an upper surface or a lower surface of the insulationmaterial and the second pad is electrically connected to the bearingplate.
 7. The power supply apparatus of claim 1, wherein the twoopposite surfaces of the bearing plate are covered with the insulationmaterial, and at least one lateral side of the bearing plate is exposedfrom the insulation material.
 8. The power supply apparatus of claim 7,further comprising: at least one second pad, wherein the second pad islocated at an upper surface or a lower surface of the insulationmaterial and the second pad is electrically connected to the bearingplate.
 9. The power supply apparatus of claim 1, wherein the bearingplate is embedded in the insulation material to form a cuboid body,edges of an upper surface and a lower surface of the cuboid body haverecesses, and two terminals of each of the pins have SMD pads extendingto the recesses at the upper surface and the lower surface of the cuboidbody.
 10. The power supply apparatus of claim 9, further comprising: aplurality of first pads disposed on lateral sides of the cuboid body,wherein the plurality of pins are electrically connected to theplurality of first pads, and the plurality of first pads areelectrically connected to the bearing plate.
 11. The power supplyapparatus of claim 9, further comprising: at least one second pad,wherein the second pad is located at the upper surface or the lowersurface of the cuboid body and the second pad is electrically connectedto the bearing plate.
 12. The power supply apparatus of claim 1, whereinthe power supply apparatus is a power unit or a control unit.
 13. Thepower supply apparatus of claim 1, wherein the power supply apparatus isa non-regulated isolated transforming module, wherein a regulated moduleis stacked on the non-regulated isolated transforming module andelectrically connected with at least one of the plurality of pins. 14.The power supply apparatus of claim 1, wherein two terminals of each ofthe pins have two SMD pads, wherein the two SMD pads of each of the pinsare extending to an upper surface and a lower surface of the insulationmaterial, respectively.
 15. A power supply apparatus, comprising: abearing plate; insulation material formed on two opposite surfaces ofthe bearing plate; and at least one pin electrically connected to thebearing plate and contacting at least part of the insulation material.16. The power supply apparatus of claim 15, further comprising: at leastone first pad disposed on a lateral side of the bearing plate, whereinthe pin is electrically connected to the first pad, and the first pad iselectrically connected to the bearing plate.
 17. The power supplyapparatus of claim 15, wherein the pin covers at least part of a lowersurface, at least part of an upper surface of the insulation materialand at least part of two lateral sides of the bearing plate.
 18. Thepower supply apparatus of claim 17, wherein at least one lateral side ofthe bearing plate is exposed from the insulation material.
 19. The powersupply apparatus of claim 17, wherein two terminals of the pin have SMDpads located at the upper surface of the insulation material.
 20. Thepower supply apparatus of claim 15, wherein the bearing plate isembedded in the insulation material to form a cuboid body, and the pincovers at least part of a lower surface, at least part of an uppersurface and at least part of two lateral sides of the cuboid body. 21.The power supply apparatus of claim 20, wherein two terminals of the pinhave SMD pads located at the upper surface of the cuboid body.